PC = Politically correct, as in "Equitable"SJW = Social Justice Warrior, as in "I advocate for an equitable society"Forced = Imposing a requirementDiversity = Concerning the diverse nature of people and their backgrounds.Virtue signalling = Demonstrating a personal belief on a public level.

So, in conclusion, what Lorcan is saying is:

Clearly this is just equitable people who are advocating for an equitable society by imposing requirements to observe the diverse nature of people and their backgrounds by demonstrating these personal beliefs in public.

A friend of mine with an autistic son has reacted very positively to this. It is not always an easy thing to explain to other children so something like this is great to see.

Sheena's friend, Chris Jackson, of Hamilton and now Bull fame helped create this character. He's written for Sesame Street for sometime (and won an Emmy for one of his songs) but this one is a bit more personal as his son has autism.

The whole effort started a couple years ago. Here's Chris' spot and the song he wrote, The Amazing Song, for Julia's introduction. I think she originally only appeared in Sesame Street books. It's good to hear they've now put her in the show.